Heating apparatus



De 8, 1959 F. o. Hass HEATING APPARATUS 3 Sheets-Sheet 1 Filed Oct. 24, 1956 R. E WH E. VO mw R E D E R F ATTORNEY.

Dec. 8, 1959 F. o. HEss HEATING APPARATUS 3 Sheets-Sheet 3 Filed Oct. 24, 1956 FIG. 3

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INVENTOR. FREDERIC O. HESS BY ,(JWW' ATTORNEY.

United States Patent O HEATING APPARATUS Frederic 0. Hess, Philadelphia, Pa., assignor to Selas Corporation of America, a corporation of Pennsylvania Application October 24, 1956, Serial No. 618,081

11 Claims. (Cl. 263-8) The present invention relates to heat treating machines, and more particularly to machines for heating bars, rods and the like of various lengths.

The invention includes an elongated furnace chamber of generally rectangular section which is constructed of a pair of members each of which is L-shaped and forms two sides of the chamber. These members can be moved relative to each other to vary the area of the chamber, and, therefore, the length of the workpieces than can be heated. Each of the members has mounted on it one section of a conveyor mechanism by which the workpieces are carried through the furnace as they are being treated.

It is an object of the invention to provide apparatus for heating rods, bars and the like. It is another objective of the invention to provide apparatus for heating elongated workpieces of various lengths.

A further object of the invention is to provide a furnace structure in which the area of the furnace chamber can be varied in accordance with the length of the workpiece that is being heated.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

In the drawings:

Fig. 1 is an elevation, partly in section, of the apparatus,

Fig. 2 is a vertical section through the apparatus taken on line 2-2 of Fig. 1, and

Fig. 3 is a horizontal section taken on line 3-3 of Fig. 2.

Referring to the drawings, there is shown a supporting structure 1 of structural steel upon which the furnace and the conveying mechanism associated therewith are mounted. The furnace includes a stationary portion 2 and a movable portion 3 which cooperate to form one elongated furnace chamber 4 that is open at the top and at the bottom. The movable section can be shifted to vary the area of the furnace chamber as rods of diferent lengths are being heated.

Furnace portion 2 is rigidly mounted on supporting structure 1 and is L-shaped in plan, having a long leg 5 and a short leg 6. This portion is constructed in accordance with ordinary furnace practice with a metal backing 7 and a refractory lining 8 both of which are suitably reinforced.

A plurality of vertically extending rows of burners 9 are located at spaced points in leg 6. Each of these burners is shown therein as being of the radiant cup type similar to that disclosed in Hess Patent 2,215,079. Such burners are characterized by having a cup shaped depression 10 formed in the furnace wall. A combustible mixture of fuel and air is supplied to the depression in a plurality of radially directed jets from a distributor 12. The mixture is burned in the cup to heat the same to incan- ICC descence so that radiant heat is directed toward the work, as well as the heat obtained from convection by the hot products of combustion. Each of the vertical rows of distributors 12 is supplied by a vertically extending manifold 13 that is provided with a valve 14. The various manifolds are, in turn, supplied by a pipe 15 that is connected to a suitable gas-air mixing machine.

Movable portion 3 of the furnace is constructed similarly to portion 2, and is also L-shaped, having a long leg 16 and a short leg 17. The long leg 16 is provided with vertical rows of burners 9 that are similar to those used in the opposite side 5 of the furnace. The rows of burners are supplied together in the manner previously described, and similar parts are given similar reference characters. It is noted that both of the pipes 15 are supplied from the same source of combustible mixture.

Movable portion 3 of the furnace is mounted on a carriage 18 that is provided with a plurality of wheels 19. These wheels roll along suitable rails 21 that extend transversely across the top of supporting structure 1. Thus it will be seen that movable portion 3 can be moved with respect to portion 2 in a direction parallel to legs 16 and 5 of the sections, respectively. Such movement varies the size of the furnace chamber without changing the spacing of the opposed rows of burners to each other or to workpieces between them, that are to be heated. Suitable asbestos or other heat resisting packing 22 is inserted in grooves provided in the ends of the short legs 5 and 17. This packing cooperates with the respective long legs of the opposite furnace portion to seal the space between the two, and thus close the furnace chamber. Portion 3 of the furnace may be moved along tracks 21, and locked in its adjusted position in any desired manner.

The workpieces to be heated are moved vertically through the furnace by a conveyor mechanism, part of which is carried by each of the furnace portions. The conveyor mechanism is described as moving the workpieces vertically downward through chamber 4. It will be apparent, however, that the workpieces could be moved upwardly if desired. The direction of movement would depend somewhat upon the location of the equipment from which the workpieces are received and to which they are delivered.

The part of the conveyor mechanism that is carried by furnace portion 2 includes an endless chain 23 that passes in a loop around leg 6 over an upper sprocket 24 and lower sprocket 25. The shaft 26 of the upper sprocket is journaled for rotation in a bearing 27 mounted on` the top of the furnace portion while sprocket 25 is mounted on a shaft 28 that is journaled for rotation in suitable bearings on supporting structure 1. It will be noted that the furnace run of chain 23 is received in a slot on channel 29 formed in leg 6. A work supporting bracket 31 is attached to and projects outwardly from each of the chain links. These brackets are each formed with an end 32 that projects through a narrow portion of slot 29 into the furnace chamber. This serves to protect the chain and most of each bracket from being subjected directly to furnace heat. The portion of the chain moving vertically upward is cooling, so that the conveyor parts are never overheated. It is noted that ends 32 can be slightly curved as best shown in Fig. 2 so that workpieces such as rods will rest in them, or they can be at or angular to support bars.

A conveyor chain 33 having work supporting brackets 34 on it, similar to that just described, is supported by sprockets 35 and 36. The furnace run of chain 33 is received in a channel in leg 17 similar to channel 29 in leg 6. Sprocket 35 is supported by a shaft that is journaled in a bracket 37 that extends upwardly from leg 17 of furnace portion 3. Sprocket 36 is attached to a shaft 38 that is journaled in bearings that are carried by suitable brackets extending from the lower end of furnace portion 2, such as that shown at 39. It is noted that these brackets must be fairly rigid since the shaft extends beyond and beneath furnace portion 2.

The conveyor chains are driven by a motor (not shown) that rotates a shaft 41 extending across supporting structure 1 and journaled in bearings 42 thereon. To this end a bevel gear 43, fixed on shaft 41, meshes with a similar gear 44 on the rear end of shaft 28. Another bevel gear 45 that rotates with shaft 41 meshes with a similar gear 46 on the rear end of shaft 3S. Gear 45 is keyed to rotate with shaft 41, but is capable of moving axially on the shaft so that it willremain in mesh with gear 46 in the various positions it will take as furnace portion 3 is moved. Thus the two chains will be driven in unison as shaft 41 is rotated.

In the operation of the apparatus, those burners which are in the furnace chamber for any particular adjustment of portion 3 are ignited. For example, three of the four rows of burners shown in each furnace portion will be ignited for the adjustment of portion 3 shown in the drawings. Valve 14 supplying the manifold connected to the outside row of burners in each section will be closed while the other valves 14 will be open. Thus the proper number of burners for any given size of furnace chamber are always available.

The workpieces to be heated, such as bars or rods, for example, are loaded either manually or automatically at the top of the furnace. This is done by placing the ends thereof on the projecting ends 32 of the brackets 31 and 34, respectively, of the opposing conveyor chains, as shown in dotted lines in the various figures of the drawings. If the projections are slightly curved, as best shown in Fig. 2, the rods will be individually supported in space relation as they are moved downwardly through the furnace chamber. By the time the rods have reached the bottom of the furnace they are up to the desired temperature. Heating of this type is a time-temperature function so that the desired temperature of the rods or bars can be obtained by varying the speed of the conveyor and/ or the temperature of the furnace. Ordinarily the furnace will be maintained at a temperature of about 2400 F so that bars 3A" by 1% can be heated to a temperature of 1800* F. at the rate of 700 per hour in a furnace 8 feet long.

When the heated bars reach the bottom of the furnace, the brackets upon which they are supported will move apart. The bars will be dropped upon a suitable discharge chute or conveyor to carry them to a forge press, for example.

lf longer or shorter bars are to be heated it is necessary first to empty the conveyor, then move portion 3 to a position in which the ends of the bars to be heated are supported by projections 32. Thereafter the rows of burners that are in the furnace chamber will be ignited.

The furnace has been described herein as being vertically positioned. It will be obvious, however, that the furnace could be disposed horizontally if it was so desired. The work would then be moved horizontally, and in some cases this might be desirable because of the location of the supply bin for the rods and the location of the forging equipment.

From the above it will be seen that I have provided a furnace having a chamber of variable size that can be used for the heating of objects of variable lengths. Regardless of the size of the furnace chamber, the work will always be kept the same distance from the burners, and the correct number of burners for any given size furnace will be available. Thus the work will always be heated in the same manner.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

l. Heat treating apparatus comprising structure forming a vertically extending furnace chamber including a portion having a vertically extending end wall and side wall, a second portion forming another end wall and side wall, means to mount said portions with thek end wall of one portion engaging the inner face of the side wall of the other, sealing means carried by said end walls to seal the crack between the two, means to move one of said portions relative to the other to vary the width of the furnace chamber, and conveyor means carried by said end walls to move articles to be heated vertically through the chamber.

2. In heating apparatus, structure forming a furnace chamber including a first elongated portion L-shaped in section with each leg of the L comprising a chamber wall, means to mount said portion in a fixed position, a second elongated portion L-shaped in section with each leg of the L comprising a chamber wall, means to mount said second portion with the legs thereof engaging the legs of said first portion with the end of the short leg of each portion engaging the inside of the long leg of the other portion to form an elongated furnace chamber rectangular in section, means to move said mounting means for said second portion in a direction parallel to said long legs to thereby change the area of said chamber, means on some of said walls to heat said chamber, and means to convey work through said chamber.

3. A heat treating machine comprising in combination structure forming a furnace chamber including a pair of elongated members L-shaped in section, means to support said members with the end of the short leg of each member engaging the inside of the long leg of the other to form a furnace chamber rectangular in section, means to move said members relative to each other parallel to the long leg thereof to vary the size of said chamber, means to heat said chamber, and means to convey work to be heated through said chamber.

4. The combination of claim 3 in which said means to heat said chamber includes burners located in the long legs of said members.

5. The combination of claim 3 in which said means to heat said chamber includes a plurality of rows of burners extending lengthwise of the long leg of said members, and means to supply fuel individually to each row of burners.

6. The combination of claim 3 in which said means to convey work includes a pair of parallel conveyor chains, means on each member to mount a conveyor chain on a short leg of each member with said chain passing in a loop around said leg lengthwise thereof, a plurality of work carrying elements on each chain, and means to drive said chains simultaneously at the same speed whereby work carried by said elements will be moved lengthwise through said chamber.

7. In heating apparatus, structure forming an elongated furnace chamber comprising a first portion substantially L-shaped in section with the legs thereof forming walls of said chamber, a second portion substantially L-shaped in section with the legs thereof forming the remaining walls of said chamber, means to mount said first portion in a fixed position, means to mount said second portion with the short legs thereof in engagement with the inside of the long legs of the other portion to form a substantially rectangular chamber, means to shift said last mentioned mounting means in the direction of one of said long legs to vary the area of said chamber, and means located in one of said legs to heat said chamber.

8. The combination of claim 7 including a first conveyor chain having Work carrying projections thereon, means to mount said chain for movement around one of the legs of one of said portions, a second conveyor chain having work carrying projections thereon, means to mount said chain for movement around a leg of the other portion forming an opposing chamber wall from said rst mentioned leg, and means to drive said chains in unison to carry work on said projections through said chamber to be heated.

9. Heating apparatus comprising in combination structure forming an elongated furnace chamber having a pair of oppositely disposed walls and an opening at each end,

veach of said walls being provided with a slot projecting inwardly from the inside surface and extending the length of the wall, a conveyer chain received in each slot, each chain having a plurality of article supporting members References Cited in the le of this patent UNITED STATES PATENTS Einfeldt Dec. 6, 1904 Dietrich Feb. 9, 1954 

